1. Field of the Invention
The present invention relates to an airbag for use in a motor vehicle. More particularly, the invention relates to sealing a side curtain airbag having multiple chambers.
2. Description of Related Art
Multi-chamber airbags are known in the art and are often used as side curtain airbags. Outer layers of material (first and second material layers) form an outer shell of the airbag and at least a third layer of material is positioned between the first and second layers of material. In general, the third material layer is connected in several areas with the outer material layers, creating a multi-chamber structure. All three, or more, material layers are connected with each other at a circumferential edge.
However, side curtain airbags are required to maintain a high internal pressure created by a gas generator for a relatively long time, as long as several seconds, in order to offer sufficient protection over the entire duration of an accident, for example, when the vehicle rolls over or in a side impact. This requires a gas impermeable airbag.
The known multi-chamber airbags weave together the three or more layers of material in an edge section. All of the material layers run together along a closed line and are woven together with one another starting at the line. The material layers must be woven relatively loosely at the edge otherwise it would not be possible to weave together all three material layers into a single continuous edge. This arrangement allows an undesirable amount of gas to leak through the edge.
In view of the above, there exists a need for an improved side curtain airbag.